From what I've heard the LS7's use a different style "Grey" iron liner. I believe that their more brittle then other liners, but were a good bang for the buck for a stock LS7. Most people looking for big power endup resleeving them. I'm sitting in the same boat right now, doing homework for a new motor. I would look into a LS3 block. On their stock bore, they seem to be pretty decent and with a slight increase in stroke, you can get up to a 427ci. I'm leaning more towards a LSX block but I'm a little concerned about core shift.

From what I've heard the LS7's use a different style "Grey" iron liner. I believe that their more brittle then other liners, but were a good bang for the buck for a stock LS7. Most people looking for big power endup resleeving them. I'm sitting in the same boat right now, doing homework for a new motor. I would look into a LS3 block. On their stock bore, they seem to be pretty decent and with a slight increase in stroke, you can get up to a 427ci. I'm leaning more towards a LSX block but I'm a little concerned about core shift.

Ok, i was wondering if the same sleeves were used in all the blocks or if they were different.

For me personally if I ever go Procharged (thrown the idea around a few times) I would just go with a set-up almost identical to yours. 390ci iron with an F1

I was just curious where there is alot of talk about ls7 popping under little boost.

Quote:

Originally Posted by SirNemesis

I'm running 30thou oversize on my LS2 block, no issues so far.

Yea I know you can go 30 over for n/a builds. With the extra heat, wouldn't you want to keep it at no more than 10 thousands over like the other guy said?

Whats the biggest enemy for the cylinder walls in a nitrous or f/i application? The additional heat created or something else?

I don't quite understand why people go with 370s. All I hear is they are a good balance in cubes and perfect for a power adder, but I think it's kinda stupid to bore it .030 over from say and ls2/lq block which are 364 stock. So why make a 370 with thinner cylinder walls, just to gain 6 cubes? Lol.

When you bore it out, you facilitate less valve shrouding with heads that use larger valves. The intake valve ends up "Shrouding" the airflow on a smaller bore motor. Boring it out, allows more room for the air to enter without it "stacking" up. I use stage 3 LS6 heads with a 2.08 intake valve and I wanted the best possible airflow I could get.

When you bore it out, you facilitate less valve shrouding with heads that use larger valves. The intake valve ends up "Shrouding" the airflow on a smaller bore motor. Boring it out, allows more room for the air to enter without it "stacking" up. I use stage 3 LS6 heads with a 2.08 intake valve and I wanted the best possible airflow I could get.